while investigating some wird referrer, I noticed that when I apply the 1st time visit segment to the Original referring domain report broken down by the Referring domain report and applying Entries metric, I can see that the numbers don't match. Shouldn't they match for the 1st time visits? Am I missing something?

I am coping pasting(With few editions) the below answer from Mishra's another reply since i understood the question.

Referring Domain and Original Referring Domain are calculated at the Hit level i.e. a single Visit can contain more than 1 line items hence visit didnt match.

Let's say I land on your site via a Google.com. This would mean my Original Referring Domain and Referring Domain currently would be Google.com. Now, I navigate on your site for 10 min. and then bookmark the page and close the tab. After 5 min. I open that bookmark again and access your site. As I came back within 30 min, the same Visit would continue; And since this time I used a bookmark, there was no Referrer, it'd in-turn update my Visit's Referring Domain to Typed/Bookmarked from Search Engine, but still my Original Referring Domain is Google.com.

As a result, now my 1 unique visit has 1 Original Referring Domain and 2 Referring Domains. Hence if you break down the visit by Referring Domain, the visit number not match.

But if you consider entries, there will be only 1 Original Referring Domain and 1 Referring Domain (Google.com). This is because, entries will not be counted for Typed/Bookmarked since it is in the same visit i.e. Within 30 minutes. So it will match!

Agreed! But if you look at my report, it says: Original Referring Domain "Typed/Bookmarked" and then broken down by entries, I get entries for various referring domain! Rather I'd expect tthe Entries to be 0 for the various referrers encountered during user journey.

But in my report I get 99% of the entries for one referrign domain! And the original referrer is direct. Something is wrong, right?

After some testing I found out there is a specific pattern as to when it is wrongly attributed. Only in case the user is entering the site directly (without referrer) and returns within the visit via a referrer, then his entry will be attributed as follows:

Original referrer = direct 1 entry

Referring domain = google.com 1 entry

So something must be wrong, I don't know if in the implementation or the attribution.

For the first time visit, Original Referring Domain and Referring Domains should be same. Even if the user break the session and come again within 30 minutes, Entries should not be assigned to the Second Referring Domain and thus you should not see any breakdown for Referring Domains in Original Referring Domain if it is 1st time visit.

Original referring domain is the referring value of the very first hit of the visitor. It can never change unless the user wipes their cache/cookies, in which case they would be considered a new visitor. There aren't many variables that persist beyond the visit, but this is one of them.

Entries as a metric means the first hit of the visit. Every visit will have exactly one entry.

So, for a practical example:

A visitor arrives via google.com, browses a few pages, then leaves.

The following day, the same visitor arrives via bing.com, then leaves.

The day after, they arrive via a bookmark, then leave once again.

Your original referring domain report would look like the following:

Original Referring Domain

Entries

Visits

google.com

3

3

The original referring domain for this user was google, and will always be google. It gets credit for everything forever. Here's the standard referring domain report: